7660

I made a laptop stand made out of a strip of mdf and two supports, it basically lifts the laptop a bit so as to give it some room the breathe, I have a small fan that runs on 24V, which I can use it on the stand to cool laptop a bit, also I didnt want to use a power adaptor or wall wart, I want to run it of the 5v from USB. After some searching, I came across many boost converter and stuff, but they were quite elaborate, I wanted something simple, few components and easy to make, I finally found boost converter IC, 7664, which would convert 5v to -5v, using just two capacitors, and this can be cascaded so by using two 7664 I could get -15V from 5V at its output, unforunately that IC was not available at the local electronics shop, but 7660 was available, the only difference was 7660 has max input voltage of 12v, and 7664 has 15 or 20V, any way the former IC will work just fine. I hooked up the circuit on a bread board and gave it a try, It worked, I got -15V at is output pin, so I connected the fan with 5V and -15v, but it didnt even budge, gave it a push it started to turn but at quite low speed, I could’nt even feel the wind because of the low current. So now I can find a fan that runs at 5v, or make a boost converter. But hey I found a easy way to get negative voltages, I think I should modify my bread board power supply with 7660 and get +5v, -5V and supply voltage.